Vermicomposting

Solid Waste Lesson Plan: Vermicomposting:
Worms with an Appetite (for Waste)! 
(Developed by the York County Solid Waste Authority © 2001) 

Ages:  4 and up 
Group Size: Up to 60

Objective 
Students examine the quiet life of the “red wiggler”. Red wigglers–also called redworms, or “Eisenia foetida”–are the primary worms used for vermicomposting (composting with worms)! Students will learn about the physical structure of this tiny biological wonder, understand the role “red wigglers” play in the environment (and in recycling leftover food waste), and investigate the concepts of waste reduction and recycling.

Method
Via a hands-on presentation, students harvest vermicompost from a finished worm bin, prepare fresh bedding for a new worm bin, and learn how to feed and maintain their “red wigglers” to produce optimum compost results.

Materials
Laptop computer with projector or overhead projector, screen or blank wall. Two worm bins with lids, flashlight, tarp, peat moss, food scraps, red wigglers, spray bottle, strips of newspaper, fabric filter, water source. All materials provided by the Authority.

Subjects/Skills
Science, biology, environmental studies. Discussion, deduction, following directions, real-life application.

Duration
40 minutes to 1 hour (adaptable to grade-appropriate length).

Setting
Indoors. Classroom.

Vocabulary Words
Vermicompost, castings, bedding, fertilize, optimal, redworm, earthworm, setae, posterior, segment, anterior, gizzard, burrow, aeration, decompose, soil, nutrients.

Background
The process of using earthworms (primarily redworms) and microorganisms to convert organic waste into nutrient-rich humus is called “vermicomposting”. From a garbage management perspective, vermicomposting benefits the environment by providing a unique option to recycle kitchen waste (food scraps, coffee grounds/filters, eggshells, and other non-fat products) into beneficial compost. Vermicomposting reduces the amount of kitchen waste that would otherwise end up in our waste stream.

Vermicomposting is easy–anyone can do it! Redworms (sometimes called “red wigglers) are the most common type of earthworm used in vermicomposting. There are many types of earthworms, so it is important to be sure that you get the right worms for the job.

The scientific name for the type of redworm used in vermicomposting is Eisenia foetida. Redworms are available from a variety of sources including garden supply shops, bait and tackle stores, and (if you are adventurous), manure piles. This particular redworm is generally the best type to use in vermicomposting because of its ability to process large amounts of organic material and reproduce rapidly in confinement. To determine how many worms will be needed to process the garbage, it must first be determined how much food waste will be generated each day. A good worm-to-garbage ratio for vermicomposting is: 2:1. For example, use four pounds of worms in your worm bin if 2 lbs. of food waste are generated per day. In general, there are approximately 1,000 worms in one pound of worms.

The proper worm bin and worm bedding is essential to a successful vermicomposting venture. Worm bins can be made of wood, metal or plastic. Redworms are surface feeders so a bin should be no deeper than 12 inches. In addition, the greater the surface area of the box, the better opportunity there is for aeration and for rotation of food that will be buried. A bin deeper than 12 inches could cause the bedding to compact and compress the air out of the bottom layers creating an anaerobic (without oxygen) condition in the bin. Both the worms and the microorganisms breaking down the food waste need oxygen to do their work. Without oxygen, anaerobic microorganisms (ones that do not require oxygen) will take over the decomposition process and in doing so, generate gases. This results in a bin with an unpleasant odor.

The bedding for the worm bin is easy to make. Shredded newsprint, a few scoops of peat moss and water are all that is needed. Bedding should be light and fluffy to encourage oxygen distribution. Be careful not to use a material that may be toxic to the worms (newspaper ink will not harm them). The soil helps to provide grit for the worms and aids in breaking down food particles in the worm’s gizzard.

Procedure
Using the audio-visual materials provided, a speaker will combine a visual presentation with audience participation to communicate key areas of emphasis. Those key areas emphasize recycling, waste reduction, vermicomposting, worm biology, and plant nutrient needs. A hands-on demonstration of how to prepare, maintain and harvest a worm bin concludes the lesson.

Evaluation Tool
Quiz questions (and answers) will be provided for teacher use. Students will be able to describe the basics of what vermicomposting is and how it works, understand the environmental benefits of vermicomposting, and relate how vermicompost is used to enhance soil nutrient value for plants.

Extensions

  1. Maintain a worm bin in the classroom for one semester. Worm bins and supplies are provided at no cost by the York County Solid Waste Authority through its “Mobile Worm Bin” program. Worm bins are available on a first-come, first-served basis. Call the Authority at 717-845-1066 to reserve a bin.
  2. Draw a diagram of a worm and label all its parts.
  3. Brainstorm all the ways worms benefit the environment. Create a school bulletin board or display illustrating the benefits.

How to Get this Lesson Plan Into Your Classroom
This lesson is available at no cost to any York County school or civic group and is presented by a member of the Authority’s Education Center staff. All materials and handouts associated with this lesson plan are provided by the Authority. Call 717-845-1066 to schedule a presentation of this lesson plan for your class or assembly program.